Topics in Geriatrics: Age-Related Systemic Changes

Objectives:

The objectives of this page are to:

1. Provide readers with a brief overview of general age-related physiological changes associated with normal human aging.
2. Discuss the importance of health and wellness screening in the geriatric population.
3. Provide readers with evidence-based tests/measures appropriate to include as part of a general health and wellness screen in the geriatric population.
4. Suggestions for management and/or prevention of detrimental physiological changes associated with aging.

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Information about Topic:

1. Structural and functional decline

• Decreased maximal aerobic capacity (VO­2max)
• Decreased skeletal muscle performance
• Variations in both measures are important determinants of exercise tolerance and functional abilities among older adults.
• Baseline values in middle-aged women and men predict future risks of disability, chronic disease, and death.
• Age-related reductions in VO2max and strength also suggest that at any submaximal exercise load, older adults are often required to exert a higher percentage of their maximal capacity (and effort) when compared to younger persons.
• Changing body composition = another hallmark of the physiological aging process, which has profound effects on health and physical function among older adults
• Gradual accumulation of body fat and its redistribution to central and visceral depots during middle age
• Loss of muscle (sarcopenia) during middle and old age, with the attendant metabolic and cardiovascular disease risks.

2. Declining physical activity

• Older populations are generally less physically active than young adults, as indicated by self-report and interview, body motion sensors, and more direct approaches for determining daily caloric expenditure.
• Although total time per day in exercise by some active older adults may approach that of younger normally active adults, the types of activities most popular among older adults are consentingly of lower intensity (walking, gardening, golf, low-impact aerobic activities).

3. Increased chronic disease risk

• The relative risk of developing and ultimately dying from many chronic diseases including cardiovascular disease, type 2 diabetes, obesity, and certain cancers increases with advancing age.
• Older populations also exhibit the highest prevalence of degenerative musculoskeletal conditions such as osteoporosis, arthritis, and sarcopenia.
• Thus, age is considered a primary risk factor for the development and progression of most chronic degenerative disease states. However, regular physical activity substantially modifies these risks.
• Additional evidence suggests that muscular strength and power also predict all- cause and cardiovascular mortality, independent of cardiovascular fitness.
• Thus, avoidance of a sedentary lifestyle by engaging in at least some daily physical activity is a prudent recommendation for reducing the risk of developing chronic diseases and postponing premature mortality at any age.

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Evidence of Age-Related Systemic Changes: Wellness Screening Tests/Measures

1. Medical Outcomes Study Questionnaire Short Form 36 Health Survey (SF-36)

• About: SF-36 is an indicator of overall health status
• Items: 10
• Reliability: Most studies that examined reliability of SF-36 have exceeded 0.80. Estimates of reliability in the physical and mental sections are typically above 0.90.
• Validity: The SF-36 is also well validated
• Scoring: The SF-36 has eight scaled scores; the scores are weighted sums of the questions in each section. Scores range from 0-100. Lower scores = more disability, higher scores = less disability
• Sections:
  • Vitality
  • Physical functioning
  • Bodily pain
  • General health perceptions
  • Physical role functioning
  • Emotional role functioning
  • Social role functioning
  • Mental health

2. Barthel Index

• Composed of 10 items investigating activities of daily living (ADLs)
• Total Score: 0-100
• Dichotomous scale: “With help,” “independent” with varying scores depending on the items
• Higher score = Higher degree of independence

3. Senior Fitness Test (SFT)

• Evaluates the functional fitness performance of older adults
• Measures the underlying physical parameters associated with functional ability, and identifies whether an older adult may be at risk for loss of functional ability
• Quick and easy to administer, requires minimal equipment, and is safe to use with a wide range of physical abilities
• Each test item has accompanying performance standards for men and women ages 60 to 94+ based on a national study of more than 7,000 Americans
• Test items:
  • Chair stand (number of stands)
  • Arm curl (number of reps)
  • 6-min walk (number of yards)
  • 2-min step (number of steps)
  • Chair Sit-&-Reach (inches +/-)
  • Back scratch (inches +/-)
  • 8-ft up-&-go (seconds)

4. Grip strength testing (dynamometer)

• Grip strength was an independent predictor of all-cause mortality and cardiovascular diseases in community-dwelling populations. (Wu, Yili et al.)
• Linear relationships were found between grip strength and risk of all-cause mortality within grip strength of 56 kg. (Wu, Yili et al.)
• Adults with multiple comorbidities demonstrated decreased grip strength as compared with those without chronic conditions. (Yorke et al.)
• Higher baseline grip strength and 5-year increase in grip strength were protective of mortality, while grip strength decline was associated with an increased risk of mortality in the elderly over 9.6 years, especially in women. These results add to the biological and clinical importance of grip strength as a powerful predictor of long-term survival in late life. (Granic et al.)
• Clinicians should consider grip strength as a component of a comprehensive physical assessment to identify decreased grip strength and recommend increased physical activity as an appropriate intervention. (Yorke et al.)

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Exercise Recommendations for Prevention of Age-Related Systemic Changes

I. Endurance exercise for older adults:


Frequency: For moderate-intensity activities, accumulate at least 30 or up to 60 (for greater benefit) min·d-1in bouts of at least 10 min each to total 150–300 min·wk-1, at least 20–30 min·d-1or more of vigorous-intensity activities to total 75–150 min·wk-1, an equivalent combination of moderate and vigorous activity.

Intensity: On a scale of 0 to 10 for level of physical exertion, 5 to 6 for moderate-intensity and 7 to 8 for vigorous intensity.

Duration: For moderate-intensity activities, accumulate at least 30 min·d-1in bouts of at least 10 min each or at least 20 min·d-1 of continuous activity for vigorous-intensity activities.

Type: Any modality that does not impose excessive orthopedic stress; walking is the most common type of activity. Aquatic exercise and stationary cycle exercise may be advantageous for those with limited tolerance for weight bearing activity.

II. Resistance exercise for older adults:

Frequency: At least 2 d·wk-1

Intensity: Between moderate- (5–6) and vigorous- (7–8) intensity on a scale of 0 to 10.

Type: Progressive weight training program or weight bearing calisthenics (8–10 exercises involving the major muscle groups of 8–12 repetitions each), stair climbing, and other strengthening activities that use the major muscle groups.

III. Flexibility exercise for older adults:

Frequency: At least 2 d·wk-1
Intensity: Moderate (5–6) intensity on a scale of 0 to 10.

Type: Any activities that maintain or increase flexibility using sustained stretches for each major muscle group and static rather than ballistic movements.

IV. Balance exercise for frequent fallers or individuals with mobility problems:


ACSM/AHA Guidelines currently recommend balance exercise for individuals who are frequent fallers or for individuals with mobility problems. Because of a lack of adequate research evidence, there are currently no specific recommendations regarding specific frequency, intensity, or type of balance exercises for older adults.

However, the ACSM Exercise Prescription Guidelines recommend using activities that include the following:
1. Progressively difficult postures that gradually reduce the base of support (e.g., two-legged stand, semitandem stand, tandem stand, one-legged stand)
2. Dynamic movements that perturb the center of gravity (e.g., tandem walk, circle turns)
3. Stressing postural muscle groups (e.g., heel stands, toe stands)
4. Reducing sensory input (e.g., standing with eyes closed).

V. The ACSM/AHA Guidelines recommend the following special considerations when prescribing exercise and physical activity for older adults.

The intensity and duration of physical activity should be low at the outset for older adults who are highly deconditioned, functionally limited, or have chronic conditions that affect their ability to perform physical tasks.
The progression of activities should be individual and tailored to tolerance and preference; a conservative approach may be necessary for the most deconditioned and physically limited older adults.
Muscle strengthening activities and/or balance training may need to precede aerobic training activities among very frail individuals. Older adults should exceed the recommended minimum amounts of physical activity if they desire to improve their fitness.
If chronic conditions preclude activity at the recommended minimum amount, older adults should perform physical activities as tolerated so as to avoid being sedentary.

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References:

1. Wu, Yili et al. “Association of Grip Strength With Risk of All-Cause Mortality, Cardiovascular Diseases, and Cancer in Community-Dwelling Populations: A Meta-analysis of Prospective Cohort Studies.” Journal of the American Medical Directors Association, Volume 18 , Issue 6 , 551.e17 - 551.e35
2. Granic et al. “Initial level and rate of change in grip strength predict all-cause mortality in very old adults.” Age Ageing. 2017 May 25:1-6. Doi: 10.1093/ageing/afx087
3. Yorke et al. “Grip strength values stratified by age, gender, and chronic disease status in adults aged 50 years and older.” J Geriatr Phys Ther. 2015 Jul-Sep;38(3):115-21. Doi:10.1519/JPT.0000000000000037
4. Makizako et al. “Effects of a community disability prevention program for frail older adults at 48-month follow up.” Geriatr Gerontol Int. 2017 Jun 18. doi: 10.1111/ggi.13072.
5. Chodzko-Zajko et al. “Exercise and Physical Activity for Older Adults: ACSM Position Stand.” Medicine & Science in Sports & Exercise. 0195-9131/09/4107-1510/0. DOI: 10.1249/MSS.0b013e3181a0c95c
6. McHorney CA, Ware JE, Lu JFR, Sherbourne CD. “The MOS 36-Item Short-Form Health Survey (SF-36®): III. tests of data quality, scaling assumptions and reliability across diverse patient groups.” Med Care1994; 32(4):40-66. 

7. Ware JE, Snow KK, Kosinski M, Gandek B. “SF-36® Health Survey Manual and Interpretation Guide.” Boston, MA: New England Medical Center, The Health Institute, 1993.
8. Ware JE, Sherbourne CD. “The MOS 36-Item Short-Form Health Survey (SF-36®): I. conceptual framework and item selection.” Med Care 1992; 30(6):473-83. 

9. Rikli RE, Jones CJ. “Measuring functional fitness of older adults.” The Journal of Active Aging. March-April 2002: 24-30.